Methods for estimating the durability of the needle bearing of the piston head of the connecting rod of a transportation diesel

The article presents the results of an experimental study and analytical evaluation calculations to check service life and increase durability of the needle bearing of piston head of connecting rod of a transport diesel engine. The primary reasons for the violation of the nominal operation of the main units of this mechanism have been established. Corresponding recommendations are proposed for carrying out accelerated tests for durability, reducing the thermal loads of the bearing operation and, as a consequence, improving the quality and service life of its entire piston group. Theoretical and experimental methods for determining the nominal life of the needle bearing of the piston head of the connecting rod (PHCR) of a transport diesel engine are proposed. The theoretical methodology allows obtaining reliable values of durability, taking into account the distribution of the working load over the rolling elements, as well as the mobility of the piston pin and sleeve. The performed calculations make it possible to correct and clarify the standard mathematical model for determining the nominal life of the PHCR needle bearing, depending on the distribution of loads on the rolling elements (rollers) under different operating conditions. This experimental technique with an acceleration factor of 10 is based on a twofold increase in the force effect on the elements of the PHCR needle bearing. This was achieved by assembling the bearing using a special technology, which is described in detail in the work. A significant decrease in the thermal effect and a decrease in radial loads on working rollers have been established. For ensure the regular oil supply into bearing during engine operation, a technique was developed to increase the load on the roller in contact zone, which significantly influenced durability and made it possible to conduct accelerated tests with a reliable yield. Its results of operational research and experience in design work correlate and are sufficiently explained by the developed methods, which allows them to be used for the improvement and modernization of connecting rods with needle bearings in PHCR. That is a permission to use these methodic for doing perfect and modern the needle bearing of the connecting-rod piston. Keywords: diesel, test procedure, needle bearing, rollers, piston head of the connecting rod, durability.

Static Structural Analysis of Different Materials for Connecting Rod

Connecting Rods are an important and irreplaceable part of IC Engines. It is responsible for converting the reciprocating motion of the piston into the rotary motion of the crankshaft. During this process, the connecting rod is subjected to various loads. Therefore, the materials used for connecting rod are also very important. In this paper, a static structural analysis of a connecting rod made of 5 different materials: Forged Steel, Carbon Steel, Stainless Steel, Grey Cast Iron and Titanium Alloy are compared. The connecting rod is analyzed only for the axial compressive load and not the axial tensile load because the tensile load is very much lesser than the compressive load. The connecting rod’s model is developed in FUSION 360 software and then imported to and analyzed using Finite Element Method in the ANSYS 2021 WORKBENCH software. The equivalent stress, total deformation along with the factor of safety for all the materials is found and compared in the analysis and all the results are shown with the help of images and graphs. Keywords: Connecting Rod, FEA, ANSYS WORKBENCH, Structural Analysis, Forged Steel, Carbon Steel, Stainless Steel, Grey Cast Iron, Titanium Alloy.

Microanalysis of Worn Surfaces of Selected Rotating Parts of an Internal Combustion Engine

The present paper analyzes the damage of surfaces at spots of frictional contact, namely, the friction nodes on a camshaft and the connecting rod pins of a crankshaft. The resulting wear of the monitored friction nodes reduces the technical life of the machines, which can lead to the decommissioning of the machine. Wear was assessed by measuring roughness and microhardness and by observing the microstructures of the materials. The results of the experiments show that the rotating parts displayed visible wear on the cams, as well as on the connecting rod pins. The experiments revealed that wear was caused by the heating of the material to a high temperature during the operation of the machine and that there was a gradual cooling and tempering of the material, which led to a reduction in the microhardness of the monitored object. Lower microhardness values can be a cause of greater wear of the monitored objects. When comparing the microhardness of the used and the new camshaft, the hardened layer of the new camshaft from secondary production has a significantly smaller thickness compared to worn cams, which leads to the finding of a different material quality compared to the original parts from primary production. This fact indicates that the wear of a new camshaft as a spare part can contribute to the shortening of the technical life of friction nodes.

Analisa Kegagalan Conrod Bearing Pada Kapal Cepat

Kerusakan conrod bearing pada main engine kapal cepat akibat design material, peningkatan panas yang berlebih pada sistem engine cooling (overheat) dan pengeoperasian. Untuk mengidentifikasi penyebab kerusakan dilaksanakan beberapa pengujian seperti pengamatan visual makro, analisis komposisi kimia, kekerasan mikro dengan vickers, fraktografi,metalografi, pengukuran ketebalan lapisan. Hasil analisis telah terjadi overheating dan deform pada conrod bearing akibat bergesekan dengan connecting rod dan terlihat pada daerah tepi alur adanya gesekan, dan tidak ditemukan lapisan babbit dikarenakan lapisan tersebut sudah lebur (fase liquid) pada temperature 354°C sesuai dengan standar logam babbit ASTM B23-00 2014 serta lapisan back steel mengalami deform.

КІНЕТОСТАТИЧНЕ ДОСЛІДЖЕННЯ ШАРНІРНИХ ПРОСТОРОВИХ МЕХАНІЗМІВ ГАЛТУВАЛЬНИХ МАШИН (ЧАСТИНА 1: ДОСЛІДЖЕННЯ МЕХАНІЗМУ З ДОДАТКОВОЮ РУХОМОЮ ЛАНКОЮ – КОРОМИСЛОМ)

Kinetostatic study of a statically determined hinged spatial mechanism without redundant (passive) connection with an additional movable link – a rocker arm of a machine for processing parts, in which the working container performs complex spatial movement. Methodology. The essence of the kinetostatic research was to determine the radial and axial components of the reactions in all rotational kinematic pairs of the hinged statically defined spatial mechanism of the machine for processing parts, when it is idling. The kinetostatic study was implemented using the SolidWorks 2016 computer-aided design system with preliminary 3D modeling of this machine design with an additional moving link – a rocker. Results. In the course of the kinetostatic study, 3D modeling of a machine with an additional movable link – a rocker arm in the SolidWorks 2016 computer-aided design system was carried out, the maximum values of the radial and axial components of reactions in all rotational kinematic pairs of the machine for processing parts were determined, the effect of changing the center distance of the intermediate connecting rod (working capacity ) on the increase in the maximum values of the reactions in all rotational kinematic pairs. Scientific novelty. The relationship between the center distance of the intermediate connecting rod (working capacity) and the change in the maximum values of the reactions in all rotational kinematic pairs of the machine for processing parts is determined. As a result, it becomes possible to determine the maximum permissible center distance of the intermediate connecting rod to ensure the durable operation of the machine. Practical significance. It is determined that the nature of the change in the maximum values of the radial and axial components of the reactions in each rotational kinematic pair of the spatial mechanism depends on the value of the coefficient characterizing the ratio of the center-to-center length of the intermediate connecting rod (working capacity) to the center-to-center length of the driving or driven connecting rods of the machine. The range of variation of this coefficient has been determined, within which it is rational to design this machine design. The results obtained can be used in the corresponding design bureaus of machine-building enterprises at the stage of designing tumbling equipment with a complex spatial movement of working containers.

Finite Element Analysis of The Thermal Behaviour of Different Types of Connecting Rod for Various Materials

Thermal analysis of different types of the connecting rods are under stead state condition using finite element method. The energy equation and heat transfer equation in the solids are completely addressed and solved using the Newton-Raphson technique and finite element method. SOLID WORKS is used for modelling different types of connecting rods and ANSYS© software is used to perform this numerical investigation. Three different materials like structural steel, aluminium alloy and titanium are selected as the material of connecting rod to do the comparative studies. In a steady thermal analysis, properties like temperature distribution, total heat flux and directional heat flux are calculated. The knowledge of the above properties is required to identify the viscosity of oil used for lubrication and also temperature distribution is helpful to find the thermal deformation in the connecting rod. Temperature and convection co-efficient are the boundary conditions. 22°C is the initial temperature value and the value of convection co-efficient is 350W/m2°C. As a result of thermal analysis, titanium alloy is the best material among the three materials as it with stand higher temperatures, high lifecycle and high performance.

On problem of calculating longitudinal vibrations of piston engine crankshaft

One of the initial stages of calculating the crankshaft longitudinal vibrations is developing an oscillatory system model, which includes the determination of longitudinal pliability (rigidity) of elastic sections. If it is impossible to determine the pliability experimental, the empiric formulas or the final element method (FEM) are used. There are given the values of crank longitudinal pliability of the crankshafts of different marine engine types found by using the formulas of L. Gugliemotti – R. Machciotta, P. Draminsky, E. Y. Gorbunov, S. F. Dorey, N. S. Skorchev, V. S. Stoyanov, etc. It is shown that the calculation results obtained from these formulas for the same engine significantly differ; therefore, the choice of one or another empirical formula for practical calculations is difficult. The preference of using FEM for determining the longitudinal (axial) compliance of cranks and other areas with complex geometric shapes has been proven. The possibility of its application is also shown to determine the longitudinal disturbing force as the reaction of the crankshaft support against the action of the radial force exerted to the connecting rod journal. It is proposed to use, along with empirical formulas, regression equations connecting the longitudinal compliance of the cranks with a significantly larger number of their design dimensions.

Study of the Kinematics and Dynamics of the Ring Pack of a Diesel Engine by Means of the Construction of CFD Model in Conjunction with Mathematical Models

The present research aims to analyze the kinematic and dynamic behavior of the piston ring package. The development of the research was carried out through the development of numerical simulation by means of CFD. The analysis involves the three piston rings for the development of simulations that are closer to the real conditions of the engine since most of the investigations tend to focus on the study of the compression ring only. The simulation was reinforced by the incorporation of mathematical models, which allow determining the piston kinematics, the lubrication properties as a function of temperature, contact friction, and gas leakage. For the simulation, the CAD of the piston and the connecting rod—crankshaft mechanism was carried out, taking as a reference the geometry of a diesel engine. From the results obtained, it was possible to show that the first ring exhibits considerably greater radial and axial movement compared to the second and third piston rings. Additionally, it was shown that the first and second rings tend to maintain a negative tilt angle throughout the combustion cycle, which facilitates the advancement of the combustion gases over the piston grooves. Therefore, it is necessary to use strategies so that these rings tend to maintain a positive inclination. The analysis of the pressure conditions in the second ring are 150% and 480% higher compared to the conditions present in the third ring. Due to the above, it is necessary to focus efforts on the design of the profile of this ring. The study of energy losses showed that the combination of leakage gases and friction are responsible for a mechanical loss between 6–16%. In general, the development of the proposed methodology is a novel tool for the joint analysis of the kinematic characteristics, pressure conditions, and energy losses. In this way, integrated analysis of changes caused by piston ring designs is possible.

Influence of operating conditions on changes in wear parameters of ICE mating

Regularities of wear of mating of internal combustion engines operated in different conditions are discussed and analyzed. Regularities of wear of part mating in the process of technical operation of a motor vehicle are obtained. The correlation coefficients and the correspondence of the obtained regularities of wear to the experimental data have been determined. According to the research results, it was determined that during intercity transportation compared to transportation in settlements, the wear rate was lower by 47.7 % for cylinder liners, by 45.8 % for piston rings, by 40.12 % for connecting rod bearings and by 39.2 % for crankshaft necks. The research results can be applied when calculating connection resources in assembly units of machines.